This is an interesting article on how Turkers react to how rewards are displayed in a crowdsourcing application:
Labor Allocation in Paid Crowdsourcing: Experimental Evidence on Positioning, Nudges and Prices by Dana Chandler (MIT) and John Horton (oDesk)
http://danachandler.com/UI-and-Economics_paper.html
They blogged about it at: http://crowdresearch.org/blog/?p=1435&utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+FollowTheCrowd+%28Follow+the+Crowd%29
Dr. Sarvapali D. Ramchurn
Lecturer (Roberts Fellow),
Intelligence, Agents, Multimedia Group,
School of Electronics and Computer Science,
University of Southampton, SO17 1BJ
t: +44 (0) 2380599309